The present invention relates to a silane compound which is a novel compound having a styrene skeleton highly homopolymerizable and copolymerizable and which is useful as, for instance, a silane coupling agent and a polymerizable monomer material.
Alkoxysilane compounds having functional organic groups have been employed as surface-treating agents for imparting various properties to the surface of a variety of substrates and polymerizable monomers for forming functional polymers through polymerization thereof with other polymerizable monomers.
As styrene type alkoxysilane compounds, there have conventionally been known, for instance, vinylbenzyl trimethoxysilane (Masanori KOKUBO et al., Collected Papers of Polymers, 1981, ,38, p. 201) and vinylphenyl trimethoxysilane (Y. KAWAKAMI et al., Polymer Journal, 1985, 17, p. 1159). However, they require, in the synthesis thereof, the use of unstable and easily polymerizable styrene type Grignard reagents (for instance, vinylbenzyl magnesium halides for the former and vinylphenyl magnesium halides for the latter) and it has been impossible to carry out such reactions in an industrial scale. Moreover, the synthesis of the foregoing compounds requires the use of a large quantity of solvents and a process for removing salts through filtration. Therefore, these compounds are very expensive.
Besides, vinylphenethyl trimethoxysilane has been known as an example of styrene type alkoxysilane compounds and can be prepared by hydrosililating divinylbenzene with hydrogen silane (see U.S. Pat. No. 3,806,549 granted to K. M. Foley). In general, preferred method for preparing alkoxysilanes having functional groups is a hydrosililating method which does not require the use of any solvent and any filtration process, which is economically favorable and which shows good workability and consequently, a variety of coupling agents have presently been synthesized according to this method. In case of the foregoing compound, however, divinylbenzene as a starting material is quite unstable and easily polymerized. Since this material has two vinyl groups having reactivities approximately identical to one another, a compound to which two silane molecules are added is easily produced during the hydrosililation thereof and thus the yield of the intended product is lowered.